The present invention relates to a power steering apparatus and a reduction mechanism for power steering.
Japanese Patent Application Public Disclosure No. 2006-224938 discloses a related technique thereto. Japanese Patent Application Public Disclosure No. 2006-224938 discusses a power steering apparatus including a ball screw mechanism. This power steering apparatus is configured in such a manner that, after reaching one end of a screw groove, balls in the ball screw mechanism return to an opposite end of the screw groove via a circulation passage.
However, the technique discussed in Japanese Patent Application Public Disclosure No. 2006-224938 has such a drawback that the size of a nut increases because the circulation passage is formed within the nut of the ball screw mechanism.